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diff --git a/lib/Transforms/Instrumentation/GCOVProfiling.cpp b/lib/Transforms/Instrumentation/GCOVProfiling.cpp
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+//===- GCOVProfiling.cpp - Insert edge counters for gcov profiling --------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass implements GCOV-style profiling. When this pass is run it emits
+// "gcno" files next to the existing source, and instruments the code that runs
+// to records the edges between blocks that run and emit a complementary "gcda"
+// file on exit.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "insert-gcov-profiling"
+
+#include "ProfilingUtils.h"
+#include "llvm/Transforms/Instrumentation.h"
+#include "llvm/Analysis/DebugInfo.h"
+#include "llvm/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/Instructions.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/DebugLoc.h"
+#include "llvm/Support/InstIterator.h"
+#include "llvm/Support/IRBuilder.h"
+#include "llvm/Support/PathV2.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/UniqueVector.h"
+#include <string>
+#include <utility>
+using namespace llvm;
+
+namespace {
+ class GCOVProfiler : public ModulePass {
+ bool runOnModule(Module &M);
+ public:
+ static char ID;
+ GCOVProfiler() : ModulePass(ID) {
+ initializeGCOVProfilerPass(*PassRegistry::getPassRegistry());
+ }
+ virtual const char *getPassName() const {
+ return "GCOV Profiler";
+ }
+
+ private:
+ // Create the GCNO files for the Module based on DebugInfo.
+ void EmitGCNO(DebugInfoFinder &DIF);
+
+ // Get pointers to the functions in the runtime library.
+ Constant *getStartFileFunc();
+ Constant *getEmitFunctionFunc();
+ Constant *getEmitArcsFunc();
+ Constant *getEndFileFunc();
+
+ // Add the function to write out all our counters to the global destructor
+ // list.
+ void InsertCounterWriteout(DebugInfoFinder &,
+ SmallVector<std::pair<GlobalVariable *,
+ uint32_t>, 8> &);
+
+ Module *Mod;
+ LLVMContext *Ctx;
+ };
+}
+
+char GCOVProfiler::ID = 0;
+INITIALIZE_PASS(GCOVProfiler, "insert-gcov-profiling",
+ "Insert instrumentation for GCOV profiling", false, false)
+
+ModulePass *llvm::createGCOVProfilerPass() { return new GCOVProfiler(); }
+
+static DISubprogram FindSubprogram(DIScope scope) {
+ while (!scope.isSubprogram()) {
+ assert(scope.isLexicalBlock() &&
+ "Debug location not lexical block or subprogram");
+ scope = DILexicalBlock(scope).getContext();
+ }
+ return DISubprogram(scope);
+}
+
+namespace {
+ class GCOVRecord {
+ protected:
+ static const char *lines_tag;
+ static const char *function_tag;
+ static const char *block_tag;
+ static const char *edge_tag;
+
+ GCOVRecord() {}
+
+ void WriteBytes(const char *b, int size) {
+ os->write(b, size);
+ }
+
+ void Write(uint32_t i) {
+ WriteBytes(reinterpret_cast<char*>(&i), 4);
+ }
+
+ // Returns the length measured in 4-byte blocks that will be used to
+ // represent this string in a GCOV file
+ unsigned LengthOfGCOVString(StringRef s) {
+ // A GCOV string is a length, followed by a NUL, then between 0 and 3 NULs
+ // padding out to the next 4-byte word. The length is measured in 4-byte words
+ // including padding, not bytes of actual string.
+ return (s.size() + 5) / 4;
+ }
+
+ void WriteGCOVString(StringRef s) {
+ uint32_t len = LengthOfGCOVString(s);
+ Write(len);
+ WriteBytes(s.data(), s.size());
+
+ // Write 1 to 4 bytes of NUL padding.
+ assert((unsigned)(5 - ((s.size() + 1) % 4)) > 0);
+ assert((unsigned)(5 - ((s.size() + 1) % 4)) <= 4);
+ WriteBytes("\0\0\0\0", 5 - ((s.size() + 1) % 4));
+ }
+
+ raw_ostream *os;
+ };
+ const char *GCOVRecord::lines_tag = "\0\0\x45\x01";
+ const char *GCOVRecord::function_tag = "\0\0\0\1";
+ const char *GCOVRecord::block_tag = "\0\0\x41\x01";
+ const char *GCOVRecord::edge_tag = "\0\0\x43\x01";
+
+ class GCOVFunction;
+ class GCOVBlock;
+
+ // Constructed only by requesting it from a GCOVBlock, this object stores a
+ // list of line numbers and a single filename, representing lines that belong
+ // to the block.
+ class GCOVLines : public GCOVRecord {
+ public:
+ void AddLine(uint32_t line) {
+ lines.push_back(line);
+ }
+
+ uint32_t Length() {
+ return LengthOfGCOVString(filename) + 2 + lines.size();
+ }
+
+ private:
+ friend class GCOVBlock;
+
+ GCOVLines(std::string filename, raw_ostream *os)
+ : filename(filename) {
+ this->os = os;
+ }
+
+ std::string filename;
+ SmallVector<uint32_t, 32> lines;
+ };
+
+ // Represent a basic block in GCOV. Each block has a unique number in the
+ // function, number of lines belonging to each block, and a set of edges to
+ // other blocks.
+ class GCOVBlock : public GCOVRecord {
+ public:
+ GCOVLines &GetFile(std::string filename) {
+ GCOVLines *&lines = lines_by_file[filename];
+ if (!lines) {
+ lines = new GCOVLines(filename, os);
+ }
+ return *lines;
+ }
+
+ void AddEdge(GCOVBlock &successor) {
+ out_edges.push_back(&successor);
+ }
+
+ void WriteOut() {
+ uint32_t len = 3;
+ for (StringMap<GCOVLines *>::iterator I = lines_by_file.begin(),
+ E = lines_by_file.end(); I != E; ++I) {
+ len += I->second->Length();
+ }
+
+ WriteBytes(lines_tag, 4);
+ Write(len);
+ Write(number);
+ for (StringMap<GCOVLines *>::iterator I = lines_by_file.begin(),
+ E = lines_by_file.end(); I != E; ++I) {
+ Write(0);
+ WriteGCOVString(I->second->filename);
+ for (int i = 0, e = I->second->lines.size(); i != e; ++i) {
+ Write(I->second->lines[i]);
+ }
+ }
+ Write(0);
+ Write(0);
+ }
+
+ ~GCOVBlock() {
+ DeleteContainerSeconds(lines_by_file);
+ }
+
+ private:
+ friend class GCOVFunction;
+
+ GCOVBlock(uint32_t number, raw_ostream *os)
+ : number(number) {
+ this->os = os;
+ }
+
+ uint32_t number;
+ BasicBlock *block;
+ StringMap<GCOVLines *> lines_by_file;
+ SmallVector<GCOVBlock *, 4> out_edges;
+ };
+
+ // A function has a unique identifier, a checksum (we leave as zero) and a
+ // set of blocks and a map of edges between blocks. This is the only GCOV
+ // object users can construct, the blocks and lines will be rooted here.
+ class GCOVFunction : public GCOVRecord {
+ public:
+ GCOVFunction(DISubprogram SP, raw_ostream *os) {
+ this->os = os;
+
+ Function *F = SP.getFunction();
+ uint32_t i = 0;
+ for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
+ blocks[BB] = new GCOVBlock(i++, os);
+ }
+
+ WriteBytes(function_tag, 4);
+ uint32_t block_len = 1 + 1 + 1 + LengthOfGCOVString(SP.getName()) +
+ 1 + LengthOfGCOVString(SP.getFilename()) + 1;
+ Write(block_len);
+ uint32_t ident = reinterpret_cast<intptr_t>((MDNode*)SP);
+ Write(ident);
+ Write(0); // checksum
+ WriteGCOVString(SP.getName());
+ WriteGCOVString(SP.getFilename());
+ Write(SP.getLineNumber());
+ }
+
+ ~GCOVFunction() {
+ DeleteContainerSeconds(blocks);
+ }
+
+ GCOVBlock &GetBlock(BasicBlock *BB) {
+ return *blocks[BB];
+ }
+
+ void WriteOut() {
+ // Emit count of blocks.
+ WriteBytes(block_tag, 4);
+ Write(blocks.size());
+ for (int i = 0, e = blocks.size(); i != e; ++i) {
+ Write(0); // No flags on our blocks.
+ }
+
+ // Emit edges between blocks.
+ for (DenseMap<BasicBlock *, GCOVBlock *>::iterator I = blocks.begin(),
+ E = blocks.end(); I != E; ++I) {
+ GCOVBlock &block = *I->second;
+ if (block.out_edges.empty()) continue;
+
+ WriteBytes(edge_tag, 4);
+ Write(block.out_edges.size() * 2 + 1);
+ Write(block.number);
+ for (int i = 0, e = block.out_edges.size(); i != e; ++i) {
+ Write(block.out_edges[i]->number);
+ Write(0); // no flags
+ }
+ }
+
+ // Emit lines for each block.
+ for (DenseMap<BasicBlock *, GCOVBlock *>::iterator I = blocks.begin(),
+ E = blocks.end(); I != E; ++I) {
+ I->second->WriteOut();
+ }
+ }
+
+ private:
+ DenseMap<BasicBlock *, GCOVBlock *> blocks;
+ };
+}
+
+void GCOVProfiler::EmitGCNO(DebugInfoFinder &DIF) {
+ DenseMap<const MDNode *, raw_fd_ostream *> gcno_files;
+ for (DebugInfoFinder::iterator I = DIF.compile_unit_begin(),
+ E = DIF.compile_unit_end(); I != E; ++I) {
+ // Each compile unit gets its own .gcno file. This means that whether we run
+ // this pass over the original .o's as they're produced, or run it after
+ // LTO, we'll generate the same .gcno files.
+
+ DICompileUnit CU(*I);
+ raw_fd_ostream *&Out = gcno_files[CU];
+ std::string ErrorInfo;
+ Out = new raw_fd_ostream(
+ (sys::path::stem(CU.getFilename()) + ".gcno").str().c_str(),
+ ErrorInfo, raw_fd_ostream::F_Binary);
+ Out->write("oncg*404MVLL", 12);
+ }
+
+ for (DebugInfoFinder::iterator SPI = DIF.subprogram_begin(),
+ SPE = DIF.subprogram_end(); SPI != SPE; ++SPI) {
+ DISubprogram SP(*SPI);
+ raw_fd_ostream *&os = gcno_files[SP.getCompileUnit()];
+
+ GCOVFunction function(SP, os);
+ Function *F = SP.getFunction();
+ for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
+ GCOVBlock &block = function.GetBlock(BB);
+ TerminatorInst *TI = BB->getTerminator();
+ if (int successors = TI->getNumSuccessors()) {
+ for (int i = 0; i != successors; ++i) {
+ block.AddEdge(function.GetBlock(TI->getSuccessor(i)));
+ }
+ }
+
+ uint32_t line = 0;
+ for (BasicBlock::iterator I = BB->begin(), IE = BB->end(); I != IE; ++I) {
+ const DebugLoc &loc = I->getDebugLoc();
+ if (loc.isUnknown()) continue;
+ if (line == loc.getLine()) continue;
+ line = loc.getLine();
+ if (SP != FindSubprogram(DIScope(loc.getScope(*Ctx)))) continue;
+
+ GCOVLines &lines = block.GetFile(SP.getFilename());
+ lines.AddLine(loc.getLine());
+ }
+ }
+ function.WriteOut();
+ }
+
+ for (DenseMap<const MDNode *, raw_fd_ostream *>::iterator
+ I = gcno_files.begin(), E = gcno_files.end(); I != E; ++I) {
+ raw_fd_ostream *&Out = I->second;
+ Out->write("\0\0\0\0\0\0\0\0", 4); // EOF
+ Out->close();
+ delete Out;
+ }
+}
+
+bool GCOVProfiler::runOnModule(Module &M) {
+ Mod = &M;
+ Ctx = &M.getContext();
+
+ DebugInfoFinder DIF;
+ DIF.processModule(*Mod);
+
+ EmitGCNO(DIF);
+
+ SmallVector<std::pair<GlobalVariable *, uint32_t>, 8> counters_by_ident;
+ for (DebugInfoFinder::iterator SPI = DIF.subprogram_begin(),
+ SPE = DIF.subprogram_end(); SPI != SPE; ++SPI) {
+ DISubprogram SP(*SPI);
+ Function *F = SP.getFunction();
+
+ // TODO: GCOV format requires a distinct unified exit block.
+ unsigned edges = 0;
+ for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
+ TerminatorInst *TI = BB->getTerminator();
+ edges += TI->getNumSuccessors();
+ }
+
+ const ArrayType *counter_type =
+ ArrayType::get(Type::getInt64Ty(*Ctx), edges);
+ GlobalVariable *counter =
+ new GlobalVariable(*Mod, counter_type, false,
+ GlobalValue::InternalLinkage,
+ Constant::getNullValue(counter_type),
+ "__llvm_gcov_ctr", 0, false, 0);
+ counters_by_ident.push_back(
+ std::make_pair(counter, reinterpret_cast<intptr_t>((MDNode*)SP)));
+
+ UniqueVector<BasicBlock *> complex_edge_preds;
+ UniqueVector<BasicBlock *> complex_edge_succs;
+
+ unsigned edge_num = 0;
+ for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
+ TerminatorInst *TI = BB->getTerminator();
+ if (int successors = TI->getNumSuccessors()) {
+ IRBuilder<> builder(TI);
+
+ if (successors == 1) {
+ Value *ctr = builder.CreateConstInBoundsGEP2_64(counter, 0, edge_num);
+ Value *count = builder.CreateLoad(ctr);
+ count = builder.CreateAdd(count,
+ ConstantInt::get(Type::getInt64Ty(*Ctx),1));
+ builder.CreateStore(count, ctr);
+ } else if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
+ Value *sel = builder.CreateSelect(
+ BI->getCondition(),
+ ConstantInt::get(Type::getInt64Ty(*Ctx), edge_num),
+ ConstantInt::get(Type::getInt64Ty(*Ctx), edge_num + 1));
+ SmallVector<Value *, 2> idx;
+ idx.push_back(Constant::getNullValue(Type::getInt64Ty(*Ctx)));
+ idx.push_back(sel);
+ Value *ctr = builder.CreateInBoundsGEP(counter,
+ idx.begin(), idx.end());
+ Value *count = builder.CreateLoad(ctr);
+ count = builder.CreateAdd(count,
+ ConstantInt::get(Type::getInt64Ty(*Ctx),1));
+ builder.CreateStore(count, ctr);
+ } else {
+ complex_edge_preds.insert(BB);
+ for (int i = 0; i != successors; ++i) {
+ complex_edge_succs.insert(TI->getSuccessor(i));
+ }
+ }
+ edge_num += successors;
+ }
+ }
+
+ // TODO: support switch, invoke, indirectbr
+ if (!complex_edge_preds.empty()) {
+ // emit a [preds x [succs x i64*]].
+ for (int i = 0, e = complex_edge_preds.size(); i != e; ++i) {
+ // call runtime to state save
+ }
+ for (int i = 0, e = complex_edge_succs.size(); i != e; ++i) {
+ // call runtime to perform increment
+ }
+ }
+ }
+
+ InsertCounterWriteout(DIF, counters_by_ident);
+
+ return true;
+}
+
+Constant *GCOVProfiler::getStartFileFunc() {
+ const Type *Args[1] = { Type::getInt8PtrTy(*Ctx) };
+ const FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx),
+ Args, false);
+ return Mod->getOrInsertFunction("llvm_gcda_start_file", FTy);
+}
+
+Constant *GCOVProfiler::getEmitFunctionFunc() {
+ const Type *Args[1] = { Type::getInt32Ty(*Ctx) };
+ const FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx),
+ Args, false);
+ return Mod->getOrInsertFunction("llvm_gcda_emit_function", FTy);
+}
+
+Constant *GCOVProfiler::getEmitArcsFunc() {
+ const Type *Args[] = {
+ Type::getInt32Ty(*Ctx), // uint32_t num_counters
+ Type::getInt64PtrTy(*Ctx), // uint64_t *counters
+ };
+ const FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx),
+ Args, false);
+ return Mod->getOrInsertFunction("llvm_gcda_emit_arcs", FTy);
+}
+
+Constant *GCOVProfiler::getEndFileFunc() {
+ const FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
+ return Mod->getOrInsertFunction("llvm_gcda_end_file", FTy);
+}
+
+static std::string ReplaceStem(std::string orig_filename, std::string new_stem){
+ return (sys::path::stem(orig_filename) + "." + new_stem).str();
+}
+
+void GCOVProfiler::InsertCounterWriteout(
+ DebugInfoFinder &DIF,
+ SmallVector<std::pair<GlobalVariable *, uint32_t>, 8> &counters_by_ident) {
+
+ const FunctionType *WriteoutFTy =
+ FunctionType::get(Type::getVoidTy(*Ctx), false);
+ Function *WriteoutF = Function::Create(WriteoutFTy,
+ GlobalValue::InternalLinkage,
+ "__llvm_gcda_writeout", Mod);
+ WriteoutF->setUnnamedAddr(true);
+ BasicBlock *BB = BasicBlock::Create(*Ctx, "", WriteoutF);
+ IRBuilder<> builder(BB);
+
+ Constant *StartFile = getStartFileFunc();
+ Constant *EmitFunction = getEmitFunctionFunc();
+ Constant *EmitArcs = getEmitArcsFunc();
+ Constant *EndFile = getEndFileFunc();
+
+ for (DebugInfoFinder::iterator CUI = DIF.compile_unit_begin(),
+ CUE = DIF.compile_unit_end(); CUI != CUE; ++CUI) {
+ DICompileUnit compile_unit(*CUI);
+ std::string filename_gcda = ReplaceStem(compile_unit.getFilename(), "gcda");
+ builder.CreateCall(StartFile,
+ builder.CreateGlobalStringPtr(filename_gcda));
+ for (SmallVector<std::pair<GlobalVariable *, uint32_t>, 8>::iterator
+ I = counters_by_ident.begin(), E = counters_by_ident.end();
+ I != E; ++I) {
+ builder.CreateCall(EmitFunction, ConstantInt::get(Type::getInt32Ty(*Ctx),
+ I->second));
+ GlobalVariable *GV = I->first;
+ unsigned num_arcs =
+ cast<ArrayType>(GV->getType()->getElementType())->getNumElements();
+ builder.CreateCall2(
+ EmitArcs,
+ ConstantInt::get(Type::getInt32Ty(*Ctx), num_arcs),
+ builder.CreateConstGEP2_64(GV, 0, 0));
+ }
+ builder.CreateCall(EndFile);
+ }
+ builder.CreateRetVoid();
+
+ InsertProfilingShutdownCall(WriteoutF, Mod);
+}
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